# US 10,872,906 B2 · Semiconductor device and manufacturing method thereof

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- Number: US 10,872,906 B2
- Document ID: US10872906B2
- Status: Granted
- Kind: B2
- Application number: 16/351,831
- Filed: 2019-03-13
- Published: 2020-04-30
- Granted: 2020-12-22
- Earliest claimed: 2018-10-25
- Assignees: Taiwan Semiconductor Manufacturing Company, Ltd.
- Applicants: Taiwan Semiconductor Manufacturing Co., Ltd.
- Inventors: Tsung-Yu Hung; Pei-Wei Lee; Pang-Yen Tsai
- Web page: https://patentgrep.com/patent/US10872906B2

## CPC

- H10D 87/00: Integrated devices comprising both bulk components and either SOI or SOS components on the same substrate
- H10D 30/751: {having composition variations in the channel regions}
- H10D 62/115: {Dielectric isolations, e.g. air gaps}
- H10D 62/832: being Group IV materials comprising two or more elements, e.g. SiGe
- H10D 64/017: {using dummy gates in processes wherein at least parts of the final gates are self-aligned to the dummy gates, i.e. replacement gate processes}
- H10D 84/0167: {Manufacturing their channels}
- H10D 84/0193: {the components including FinFETs}
- H10D 84/038: {using silicon technology, e.g. SiGe}
- H10D 84/853: {comprising FinFETs}
- H10D 86/011: {comprising FinFETs}
- H10D 86/215: {comprising FinFETs}
- H10P 14/24: using chemical vapour deposition [CVD]
- H10P 14/271: {characterised by the preparation of substrate for selective deposition}
- H10P 14/2905: {Silicon, silicon germanium or germanium}
- H10P 14/3211: {Silicon, silicon germanium or germanium}
- H10P 14/3248: {consisting of two layers}
- H10P 14/3258: {Crystal orientation}
- H10P 14/3411: {Silicon, silicon germanium or germanium}
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

A semiconductor device includes a substrate, a first semiconductor fin and a gate stack. The first semiconductor fin is over the substrate and includes a first germanium-containing layer and a second germanium-containing layer over the first germanium-containing layer. The first germanium-containing layer has a germanium atomic percentage higher than a germanium atomic percentage of the second germanium-containing layer. The gate stack is across the first semiconductor fin.

## Claims

### Claim 1

A semiconductor device, comprising:
a substrate;
a first semiconductor fin over the substrate and comprising a first germanium-containing layer and a second germanium-containing layer over the first germanium-containing layer, wherein the first germanium-containing layer has a germanium atomic percentage higher than a germanium atomic percentage of the second germanium-containing layer, and the first germanium-containing layer is asymmetric with respect to an axis of the first semiconductor fin; and
a gate stack across the first semiconductor fin.

### Claim 2 (depends on 1)

The semiconductor device of claim 1, wherein the first semiconductor fin further comprises a third germanium-containing layer under the first germanium-containing layer and having a germanium atomic percentage lower than the germanium atomic percentage of the first germanium-containing layer.

### Claim 3 (depends on 2)

The semiconductor device of claim 2, wherein a germanium atomic percentage difference between the first and second germanium-containing layers is greater than a germanium atomic percentage difference between the second and third germanium-containing layers.

### Claim 4 (depends on 2)

The semiconductor device of claim 2, wherein a germanium atomic percentage difference between the first and third germanium-containing layers is greater than a germanium atomic percentage difference between the second and third germanium-containing layers.

### Claim 5 (depends on 2)

The semiconductor device of claim 2, wherein the germanium atomic percentage of the second germanium-containing layer is substantially the same as the germanium atomic percentage of the third germanium-containing layer.

### Claim 6 (depends on 2)

The semiconductor device of claim 2, wherein an interface between the first and third germanium-containing layers is on a (111) plane.

### Claim 7 (depends on 1)

The semiconductor device of claim 1, wherein an interface between the first and second germanium-containing layers is on a (111) plane.

### Claim 8 (depends on 1)

The semiconductor device of claim 1, further comprising:
a second semiconductor fin over the substrate, wherein the second semiconductor fin has a top end in a position higher than a top end of an interface between the first and second germanium-containing layers.

### Claim 9 (depends on 8)

The semiconductor device of claim 8, further comprising:
a dielectric layer between the second semiconductor fin and the substrate.

### Claim 10 (depends on 9)

The semiconductor device of claim 9, wherein an interface between the dielectric layer and the second semiconductor fin is in a position lower than a bottom end of the interface between the first and second germanium-containing layers.

### Claim 11

A semiconductor device, comprising:
a substrate;
a first semiconductor fin protruding above the substrate, the first semiconductor fin comprising a first germanium-containing layer and a second germanium-containing layer having a germanium atomic percentage lower than a germanium atomic percentage of the first germanium-containing layer; and
a p-type epitaxy region wrapping around three sides of the first semiconductor fin, the second germanium-containing layer being between the p-type epitaxy region and the first germanium-containing layer.

### Claim 12 (depends on 11)

The semiconductor device of claim 11, further comprising:
a second semiconductor fin protruding above the substrate and having a germanium atomic percentage lower than the germanium atomic percentage of the first germanium-containing layer of the first semiconductor fin.

### Claim 13 (depends on 12)

The semiconductor device of claim 12, wherein the germanium atomic percentage of the second semiconductor fin is substantially the same as the germanium atomic percentage of the second germanium-containing layer of the first semiconductor fin.

### Claim 14 (depends on 12)

The semiconductor device of claim 12, further comprising:
a third semiconductor fin protruding above the substrate and free of germanium.

### Claim 15 (depends on 11)

The semiconductor device of claim 11, wherein the p-type epitaxy region is interfaced with the first and second germanium-containing layers.

### Claim 16 (depends on 11)

The semiconductor device of claim 11, wherein the first semiconductor fin further comprises a third germanium-containing layer between the first germanium-containing layer and the substrate, and the third germanium-containing layer has a germanium atomic percentage lower than the germanium atomic percentage of the first germanium-containing layer.

### Claim 17 (depends on 16)

The semiconductor device of claim 16, wherein the germanium atomic percentage of the second germanium-containing layer is substantially the same as the germanium atomic percentage of the third germanium-containing layer.

### Claim 18

A method, comprising:
etching a hybrid substrate to form a recess extending into the hybrid substrate, wherein the hybrid substrate comprises a first semiconductor layer having a first surface orientation, a dielectric layer over the first semiconductor layer, and a second semiconductor layer having a second surface orientation different from the first surface orientation, wherein after the etching, a top surface of the first semiconductor layer is exposed to the recess;
forming a spacer on a sidewall of the recess;
performing a first epitaxy process to grow a first germanium-containing layer from the exposed top surface of the first semiconductor layer;
performing a second epitaxy process to grow a second germanium-containing layer from the first germanium-containing layer, wherein a flow rate of a germanium-containing gas used in the second epitaxy process is less than a flow rate of a germanium-containing gas used in the first epitaxy process; and
patterning the first and second germanium-containing layers to form a fin.

### Claim 19 (depends on 18)

The method of claim 18, wherein the first epitaxy process is performed such that the first germanium-containing layer comprises a first portion grown from the first semiconductor layer and a second portion grown from a facet of the first portion, the facet is on a (111) plane, and the second portion has a germanium atomic percentage higher than a germanium atomic percentage of the first portion.

### Claim 20 (depends on 19)

The method of claim 19, wherein the second epitaxy process is performed such that at least a portion of the second germanium-containing layer is grown from the second portion.